The present invention relates generally to the reclaiming of metal from by-products and scrap, and more particularly, to an improved well-type melting furnace and process for use therewith.
In the recovery of metals from scrap materials, some of the greatest problems have been presented by scrap contaminated with combustibles, particularly hydrocarbons, such as oil, paint, grease and the like. Such hydrocarbon-contaminated materials have required rather elaborate processing to drive off by vaporization as much of the hydrocarbon contaminant as possible while avoiding oxidation of the metal, which would decrease recovery. The processing of such scrap results in production of fully or partially unburned hydrocarbon-bearing fumes which previously were wasted and which added a further problem of pollution. A superior solution to these problems for rotary furnaces, involving in situ utilization of the combustible vapors as fuel for the melting process, has been set forth in the copending application of Robert G. Snyder, et al, "Method of Reclaiming Metal from Scrap Materials," Ser. No. 59,640, filed 7/30/70, and now assigned to the same assignee as the present invention now abandoned.
The well-type melting furnace which is often used for such recovery operations has presented certain additional problems peculiar to its own design. Such a well-type furnace consists of a vertically-extending central heating chamber over a well which extends horizontally both within and on at least one side thereof, outside the heating chamber. The outside well portion of the furnace normally has been open to permit fumes of unburned hydrocarbons and other combustibles to escape and dissipate in the surrounding atmosphere. Due to the design of the furnace, it has been proven difficult to dispose of such fumes without disturbing its operation.